1. Field of the Invention
This invention relates to an optical disc such as a phase change optical disc or a magneto-optical disc. In addition, this invention relates to an apparatus for recording a digital information signal on an optical disc. Furthermore, this invention relates to an apparatus for reproducing a digital information signal from an optical disc. Also, this invention relates to an apparatus for recording and reproducing a digital information signal on and from an optical disc.
2. Description of the Related Art
A DVD-RW (DVD Rewritable) has a disc member formed with a spiral of a wobbling groove on and from which main information can be recorded and reproduced. The disc member has land portions between neighboring groove portions. A groove portion and a pair of land portions adjoining the groove portion compose a track portion. Auxiliary information (a land pre-pit signal) is previously recorded on the land portions. Specifically, the auxiliary information is represented by land pre-pits formed in the land portions.
Japanese patent application publication number 9-326138 discloses an optical disc formed with wobbling grooves and pits (land pre-pits). The pits are located in an area between the grooves, and are spaced at a prescribed interval. During the recording of a signal on the disc or the reproduction of a signal therefrom, rotation of the disc is controlled in response to a wobble signal detected from the grooves. In addition, the position of a point on the disc is detected from a pit signal (a land pre-pit signal) derived from the pits.
The DVD-RW and the optical disc in Japanese patent application publication number 9-326138 are subjected to CLV (constant linear velocity) control during signal recording or signal reproduction. The CLV control causes the following problems.
(1) The phases of neighboring wobbles become opposite at some places. At these places, the cross-talks between a desired signal reproduced from the currently-scanned track and signals on tracks neighboring the currently-scanned track are relatively great. Accordingly, these places have a bad influence on signal recording. The quality of a land pre-pit signal reproduced from these places tends to be relatively low.
(2) In the case of data seek which requires an optical head to move radially of the disc for a large distance, a long time is taken until the rotational speed of the disc falls into a suitable range.
(3) If land pre-pits along neighboring tracks had equal phases, signal reproduction could be unavailable. Accordingly, it is necessary to design land pre-pits along neighboring tracks to have different phases.
Japanese patent application publication number 10-255330 discloses an optical disc having wobbling grooves which are designed to equalize the phases of the wobbles of neighboring grooves. The optical disc in Japanese patent application publication number 10-255330 can solve the above-indicated problem (1).
It is a first object of this invention to provide an improved optical disc.
It is a second object of this invention to provide an improved apparatus for recording a digital information signal on an optical disc.
It is a third object of this invention to provide an improved apparatus for reproducing a digital information signal from an optical disc.
It is a fourth object of this invention to provide an improved apparatus for recording and reproducing a digital information signal on and from an optical disc.
A first aspect of this invention provides an optical disc having an information recording portion, the information recording portion having a spiral of a groove, the information recording portion having land portions located between portions of the groove which neighbor each other as viewed in a disc radial direction, wherein auxiliary information used when an information signal is recorded on and reproduced from the groove is previously recorded on the land portions, wherein the auxiliary information is represented by pre-pits provided in the land portions, wherein the information recording portion is divided into a plurality of zones as viewed in the disc radial direction, wherein in each of the zones, at least one of two sides of the groove wobbles at a fixed frequency in accordance with a constant angular velocity system, and wherein in each of the zones, phases of wobbles of respective neighboring portions of the groove are equal to each other, and the neighboring portions of the groove neighbor each other as viewed in the disc radial direction.
A second aspect of this invention is based on the first aspect thereof, and provides an optical disc wherein the pre-pits are at positions having approximately a fixed relation with a period of the wobble of the groove, wherein groups each having a predetermined number of pre-pit locations represent bit data values containing addresses of the zones, and wherein a pre-pit is present in or absent from each of the pre-pit locations.
A third aspect of this invention is based on the second aspect thereof, and provides an optical disc wherein the groups in first one of the land portions are at first positions, and the groups in second one of the land portions are at second positions, wherein the first one of the land portions and the second one of the land portions neighbor each other as viewed in the disc radial direction, and wherein a phase of the first positions differ from a phase of the second positions as viewed along a disc circumferential direction.
A fourth aspect of this invention is based on the second aspect thereof, and provides an optical disc wherein the groups have first groups each representing a bit data value of xe2x80x9c1xe2x80x9d and second groups each representing a bit data value of xe2x80x9c0xe2x80x9d, wherein each of the first groups and each of the second groups are equal in number of pre-pits per group, and wherein each of the first groups and each of the second groups are different in arrangement of pre-pits per group.
A fifth aspect of this invention is based on the first aspect thereof, and provides an optical disc wherein the frequency xe2x80x9cfwxe2x80x9d of the wobble of the groove and a channel bit clock frequency xe2x80x9cfpxe2x80x9d of the information signal are in a relation as follows:
fp=Nxc2x7fw
where N denotes a natural number.
A sixth aspect of this invention is based on the first aspect thereof, and provides an optical disc wherein as the zone changes from one to the next in a disc radially outward direction, a number of cycles of the wobble increases by a predetermined natural number and an amount of the information signal increases by a predetermined number of recording units.
A seventh aspect of this invention is based on the first aspect thereof, and provides an optical disc wherein the information recording portion is divided into a plurality of sectorial segments of equal angular sizes, and wherein as the zone changes from one to the next in a disc radially outward direction, a number of cycles of the wobble per sectorial segment increases by a predetermined natural number and an amount of the information signal per sectorial segment increases by a predetermined number of recording units.
An eighth aspect of this invention provides an apparatus for recording digital information on an optical disc having an information recording portion, the information recording portion having a spiral of a groove, the information recording portion having land portions located between portions of the groove which neighbor each other as viewed in a disc radial direction, wherein auxiliary information used when an information signal is recorded on and reproduced from the groove is previously recorded on the land portions, wherein the auxiliary information is represented by pre-pits provided in the land portions, wherein the information recording portion is divided into a plurality of zones as viewed in the disc radial direction, wherein in each of the zones, at least one of two sides of the groove wobbles at a fixed frequency xe2x80x9cfwxe2x80x9d in accordance with a constant angular velocity system, wherein in each of the zones, phases of wobbles of respective neighboring portions of the groove are equal to each other, and the neighboring portions of the groove neighbor each other as viewed in the disc radial direction, and wherein the wobble frequency xe2x80x9cfwxe2x80x9d and a channel bit clock frequency xe2x80x9cfpxe2x80x9d of the information signal are in a relation as follows:
fp=Nxc2x7fw
where N denotes a natural number. The apparatus comprises signal reproducing means for reproducing a signal from the optical disc to generate a reproduced signal; pre-pit reproducing means for detecting the pre-pits in response to the reproduced signal, and generating a pre-pit signal representative of the detected pre-pits; wobble reproducing means for detecting the wobble in response to the reproduced signal, and generating a wobble signal representative of the detected wobble; clock generating means for generating a recording clock signal in response to the pre-pit signal and the wobble signal; zone address generating means for generating zone address information representative of addresses of the zones in response to the pre-pit signal; and recording means for recording an information signal on the groove in synchronism with the recording clock signal and in response to the zone address information and a reference clock signal having a frequency related to the wobble frequency, wherein the recording of the information signal is in accordance with a constant angular velocity system in each of the zones.
A ninth aspect of this invention provides an apparatus for reproducing digital information from an optical disc having an information recording portion, the information recording portion having a spiral of a groove, the information recording portion having land portions located between portions of the groove which neighbor each other as viewed in a disc radial direction, wherein auxiliary information used when an information signal is recorded on and reproduced from the groove is previously recorded on the land portions, wherein the auxiliary information is represented by pre-pits provided in the land portions, wherein the information recording portion is divided into a plurality of zones as viewed in the disc radial direction, wherein in each of the zones, at least one of two sides of the groove wobbles at a fixed frequency xe2x80x9cfwxe2x80x9d in accordance with a constant angular velocity system, wherein in each of the zones, phases of wobbles of respective neighboring portions of the groove are equal to each other, and the neighboring portions of the groove neighbor each other as viewed in the disc radial direction, and wherein the wobble frequency xe2x80x9cfwxe2x80x9d and a channel bit clock frequency xe2x80x9cfpxe2x80x9d of the information signal are in a relation as follows:
fp=Nxc2x7fw
where N denotes a natural number. The apparatus comprises signal reproducing means for reproducing a signal from the optical disc to generate a reproduced signal; pre-pit reproducing means for detecting the pre-pits in response to the reproduced signal, and generating a pre-pit signal representative of the detected pre-pits; zone address generating means for generating zone address information representative of addresses of the zones in response to the pre-pit signal; and information reproducing means for reproducing an information signal from the groove in response to the zone address information and a reference clock signal having a frequency related to the wobble frequency, wherein the reproduction of the information signal is in accordance with a constant angular velocity system in each of the zones.
A tenth aspect of this invention provides an optical disc having an information recording portion, the information recording portion having concentric grooves, the information recording portion having lands located between the grooves, wherein auxiliary information used when an information signal is recorded on and reproduced from the grooves is previously recorded on the lands, wherein the auxiliary information is represented by pre-pits provided in the lands, wherein the information recording portion is divided into a plurality of zones as viewed in a disc radial direction, wherein in each of the zones, at least one of two sides of each of the grooves wobbles at a fixed frequency in accordance with a constant angular velocity system, and wherein in each of the zones, phases of wobbles of neighboring ones of the grooves are equal to each other.
An eleventh aspect of this invention provides an optical disc having an information recording portion, the information recording portion having a spiral of a groove, the information recording portion having land portions located between portions of the groove which neighbor each other as viewed in a disc radial direction, wherein auxiliary information used when an information signal is recorded on and reproduced from the groove is previously recorded on the land portions, wherein the auxiliary information is represented by pre-pits provided in the land portions, wherein the information recording portion is divided into a plurality of zones as viewed in the disc radial direction, wherein in each of the zones, at least one of two sides of the groove wobbles at a fixed frequency in accordance with a constant angular velocity system, and wherein in each of the zones, phases of wobbles of respective neighboring portions of the groove are equal to each other, and the neighboring portions of the groove neighbor each other as viewed in the disc radial direction, the optical disc further having at least one connection track extending in one of two neighboring zones among the zones and along a boundary between the two neighboring zones, the connection track including a portion among the portions of the groove and a land portion among the land portions, wherein the land portion in the connection track is devoid of pre-pits, and the portion of the groove in the connection track is equal in wobble cycle and wobble phase to portions of the groove in the zone containing the connection track.
A twelfth aspect of this invention is based on the eleventh aspect thereof, and provides an optical disc wherein the portion of the groove in the connection track includes at least one of a total reflection mirror region and a region representative of predetermined pit information.
A thirteenth aspect of this invention provides an apparatus for recording and reproducing digital information on and from an optical disc having an information recording portion, the information recording portion having a spiral of a groove, the information recording portion having land portions located between portions of the groove which neighbor each other as viewed in a disc radial direction, wherein auxiliary information used when an information signal is recorded on and reproduced from the groove is previously recorded on the land portions, wherein the auxiliary information is represented by pre-pits provided in the land portions, wherein the information recording portion is divided into a plurality of zones as viewed in the disc radial direction, wherein in each of the zones, at least one of two sides of the groove wobbles at a fixed frequency in accordance with a constant angular velocity system, and wherein in each of the zones, phases of wobbles of respective neighboring portions of the groove are equal to each other, and the neighboring portions of the groove neighbor each other as viewed in the disc radial direction, the optical disc further having at least one connection track extending in one of two neighboring zones among the zones and along a boundary between the two neighboring zones, the connection track including a portion among the portions of the groove and a land portion among the land portions, wherein the land portion in the connection track is devoid of pre-pits, and the portion of the groove in the connection track is equal in wobble cycle and wobble phase to portions of the groove in the zone containing the connection track. The apparatus comprises reproducing means for reproducing a signal from the optical disc to generate a reproduced signal; pre-pit detecting means for detecting a pre-pit signal from the reproduced signal, the pre-pit signal representing the pre-pits; pre-pit decoding means for decoding the pre-pit signal detected by the pre-pit detecting means into original pre-pit information; and connection track detecting means for detecting a connection track in response to the original pre-pit information generated by the pre-pit decoding means, and generating connection track information representative of the detected connection track.
A fourteenth aspect of this invention is based on the thirteenth aspect thereof, and provides an apparatus further comprising means for inverting a polarity of the pre-pit signal in response to the connection track information.
A fifteenth aspect of this invention provides an optical disc having an information recording portion, the information recording portion having concentric grooves, the information recording portion having lands located between the grooves, wherein auxiliary information used when an information signal is recorded on and reproduced from the grooves is previously recorded on the lands, wherein the auxiliary information is represented by pre-pits provided in the lands, wherein the information recording portion is divided into a plurality of zones as viewed in a disc radial direction, wherein in each of the zones, at least one of two sides of each of the grooves wobbles at a fixed frequency in accordance with a constant angular velocity system, and wherein in each of the zones, phases of wobbles of neighboring ones of the grooves are equal to each other, the optical disc further having at least one connection track extending in one of two neighboring zones among the zones and along a boundary between the two neighboring zones, the connection track including a groove among the grooves and a land among the lands, wherein the land in the connection track is devoid of pre-pits, and the groove in the connection track is equal in wobble cycle and wobble phase to the grooves in the zone containing the connection track.
A sixteenth aspect of this invention provides an apparatus for recording digital information on an optical disc having an information recording portion, the information recording portion having concentric grooves, the information recording portion having lands located between the grooves, wherein auxiliary information used when an information signal is recorded on and reproduced from the grooves is previously recorded on the lands, wherein the auxiliary information is represented by pre-pits provided in the lands, wherein the information recording portion is divided into a plurality of zones as viewed in a disc radial direction, wherein in each of the zones, at least one of two sides of each of the grooves wobbles at a fixed frequency xe2x80x9cfwxe2x80x9d in accordance with a constant angular velocity system, wherein in each of the zones, phases of wobbles of neighboring ones of the grooves are equal to each other, and wherein the wobble frequency xe2x80x9cfwxe2x80x9d and a channel bit clock frequency xe2x80x9cfpxe2x80x9d of the information signal are in a relation as follows:
fp=Nxc2x7fw
where N denotes a natural number. The apparatus comprises signal reproducing means for reproducing a signal from the optical disc to generate a reproduced signal; pre-pit reproducing means for detecting the pre-pits in response to the reproduced signal, and generating a pre-pit signal representative of the detected pre-pits; wobble reproducing means for detecting the wobble in response to the reproduced signal, and generating a wobble signal representative of the detected wobble; clock generating means for generating a recording clock signal in response to the pre-pit signal and the wobble signal; zone address generating means for generating zone address information representative of addresses of the zones in response to the pre-pit signal; and recording means for recording an information signal on the grooves in synchronism with the recording clock signal and in response to the zone address information and a reference clock signal having a frequency related to the wobble frequency, wherein the recording of the information signal is in accordance with a constant angular velocity system in each of the zones.
A seventeenth aspect of this invention provides an apparatus for reproducing digital information from an optical disc having an information recording portion, the information recording portion having concentric grooves, the information recording portion having lands located between the grooves, wherein auxiliary information used when an information signal is recorded on and reproduced from the grooves is previously recorded on the lands, wherein the auxiliary information is represented by pre-pits provided in the lands, wherein the information recording portion is divided into a plurality of zones as viewed in a disc radial direction, wherein in each of the zones, at least one of two sides of each of the grooves wobbles at a fixed frequency xe2x80x9cfwxe2x80x9d in accordance with a constant angular velocity system, wherein in each of the zones, phases of wobbles of neighboring ones of the grooves are equal to each other, and wherein the wobble frequency xe2x80x9cfwxe2x80x9d and a channel bit clock frequency xe2x80x9cfpxe2x80x9d of the information signal are in a relation as follows:
fp=Nxc2x7fw
where N denotes a natural number. The apparatus comprises signal reproducing means for reproducing a signal from the optical disc to generate a reproduced signal; pre-pit reproducing means for detecting the pre-pits in response to the reproduced signal, and generating a pre-pit signal representative of the detected pre-pits; zone address generating means for generating zone address information representative of addresses of the zones in response to the pre-pit signal; and information reproducing means for reproducing an information signal from the grooves in response to the zone address information and a reference clock signal having a frequency related to the wobble frequency, wherein the reproduction of the information signal is in accordance with a constant angular velocity system in each of the zones.
An eighteenth aspect of this invention provides an apparatus for recording and reproducing digital information on and from an optical disc having an information recording portion, the information recording portion having concentric grooves, the information recording portion having lands located between the grooves, wherein auxiliary information used when an information signal is recorded on and reproduced from the grooves is previously recorded on the lands, wherein the auxiliary information is represented by pre-pits provided in the lands, wherein the information recording portion is divided into a plurality of zones as viewed in a disc radial direction, wherein in each of the zones, at least one of two sides of each of the grooves wobbles at a fixed frequency in accordance with a constant angular velocity system, and wherein in each of the zones, phases of wobbles of neighboring ones of the grooves are equal to each other, the optical disc further having at least one connection track extending in one of two neighboring zones among the zones and along a boundary between the two neighboring zones, the connection track including a groove among the grooves and a land among the lands, wherein the land in the connection track is devoid of pre-pits, and the groove in the connection track is equal in wobble cycle and wobble phase to the grooves in the zone containing the connection track. The apparatus comprises reproducing means for reproducing a signal from the optical disc to generate a reproduced signal; pre-pit detecting means for detecting a pre-pit signal from the reproduced signal, the pre-pit signal representing the pre-pits; pre-pit decoding means for decoding the pre-pit signal detected by the pre-pit detecting means into original pre-pit information; and connection track detecting means for detecting a connection track in response to the original pre-pit information generated by the pre-pit decoding means, and generating connection track information representative of the detected connection track.